Well, there is the Amy attraction to Penny shtick. “Gimme some sugar, Betsy!”
but again, it’s made fun of, and Penny rejects it - and Amy’s attractions to Sheldon are far more prevalent. Same when Raj and Stuart have one of those awkward moments - it is lampooned.
No gay agenda - in fact, the opposite. Think about it: almost every show has at least one gay character or gay couple among the regulars. BBT does not. Quickly I ran through 14 regulars or semi regulars, and zip zero nada.