Yes, we need to be careful not to read things into the scriptures. This is what Gill states:
And there followed him a certain young man,.... Some think this was John, the beloved disciple, and the youngest of the disciples; others, that it was James, the brother of our Lord; but he does not seem to be any of the disciples of Christ, since he is manifestly distinguished from them, who all forsook him and fled: some have thought, that he was a young man of the house, where Christ and his disciples ate their passover; who had followed him to the garden, and still followed him, to see what would be the issue of things: but it seems most likely, that he was one that lived in an house in Gethsemane, or in or near the garden; who being awaked out of sleep with the noise of a band of soldiers, and others with them, leaped out of bed, and ran out in his shirt, and followed after them, to know what was the matter:
No one really seems to know. I just like to think the best happened.
The part that makes it likely in this case that it was a pure calling is that it is preceded with the lines about Jesus loving the young man.
As far as Jesus loving the man and then calling him, this is what Gill states:
Then Jesus, beholding him, loved him,.... Not as God, with that special love, with which he loves his people, who were given him by the Father, are redeemed by his blood, whom he calls by his grace, justifies by his righteousness, forgives their iniquities, and, at last, glorifies: but as man, he had an human affection for him; so far as there was any appearance of moral good in him, it was agreeable to him, who loves righteousness, and hates iniquity; and though the young man betrayed much vanity, pride, and conceit, he did not use him roughly, but kindly, and tenderly; he beheld him, he looked wistly upon him, when he said the above words; which look intimated, that he could not believe he had perfectly, and completely kept all the commandments; however, he did not choose to reproach him with a lie, and charge him with pride and arrogance, but gave him good words, and spoke friendly to him; and, as far as he could, commended him for his diligence in observing the commands: in this sense the word is observed to be used by the Septuagint interpreters, as when it is said of Ahab, 2Ch_18:2, that he "persuaded him" (Jehoshaphat), they render it, ηγαπα, "he loved him to go up to Ramoth Gilead": he gave him good words, he spake friendly to him, and by fair speeches prevailed upon him: and so when it said of the Israelites, Psa_78:36; "they did flatter him", (God,) they render it, ηγαπησαν, "they loved him with their mouth"; spoke very well to him, and of him, praised him, and his works, and in this way expressed affection to him, though it was only with their mouths. Moreover, Christ might not only speak kindly to this young man, but he might make use of some external gesture: which showed an human affection to him, and respect for him. Dr, Lightfoot conjectures it might be by kissing his head, which might be conveniently done, as he was now on his knees; and since this was frequently used by the Jewish doctors, as an expression of respect, of which he gives various instances; and more might be added, especially out of the book of Zohar, where we often read of one Rabbi kissing the head or another, or of his pupil. But the sense of this phrase, which pleases me best of all, is what may be collected from the use of it among the "seventy" interpreters, who often render the Hebrew רחם, which signifies to "have compassion", or "show pity", by the word here used: so Pro_28:13, "whoso confesseth and forsaketh, shall have mercy", they interpret αγαπηθησεται, "shall be loved" and Hos_2:23, "I will have mercy on her that had not obtained mercy", they render αγαπησω, "l will love her that was not beloved"; once more, Zec_10:6. "I will bring them again to place them, for I have mercy upon them", they translate οτι ηγαπησα αυτους, "because I have loved them"; see also Isa_60:10 and then, according to this use of the word, the sense is, that Jesus looked upon him when he expressed himself in such a pert manner, and had a compassionate concern for him; he pitied him for his ignorance of the law, in its spirituality and large extent; for his pride and vanity, his conceit of, and glorying in himself: wherefore, in order to mortify him, and abate these swelling thoughts of himself; he said unto him, one thing thou lackest; before which last clause the Ethiopic version puts this, "if thou wilt be perfect", out of Mat_19:21, see the note there: and the Coptic version, and two of Stephens's copies read it before the following,
go thy way, sell whatsoever thou hast, and give to the poor, and thou shalt have treasure in heaven; and come, take up the cross, and follow me. This young man's reigning sin seems to have been an overweening affection for the things of this world; his riches were his idol, on which his heart was set, and in which he trusted: wherefore he was so far from keeping all the commandments, that he had not kept the first; "thou shalt have no other gods before me": there was more than one thing wanting in him, but Christ takes notice of this as the first; and there was no need to mention any other; this touched him sensibly, and fully tried, and sufficiently exposed the vanity of his boasted perfection. That clause, "take up the cross", is omitted in the Vulgate Latin version, as it is not mentioned by Matthew. The Ethiopic version reads it, "the cross of thy death", and places it before, "come and follow me"; as do also the Syriac and Persic versions; but the Arabic reads it last of all;
Gill seems to be saying that the Lord had regard or liking for the man rather than love.
However, if we assume that the Lord was incapable of feigned regard or feigned liking or feigned offers, then we still have the Lord making a serious offer to the young man.
“Sell what you have and come, follow me.”