[Malesherbes]

Mr. Gonya "attends mass at two churches every Sunday." Correct me if I'm wrong, but I don't believe the Church allows attendance at mass twice on the same day.

[Francis McClobber]

One can attend as many masses as one wishes; one may only receive communion once in a day.

[SuziQ]

You can attend as many Masses on Sunday as you like, but you're only supposed to receive Holy Communion once in a day.

[pbear8]

You can go to Mass as many times as you want in one day. However you can receive Holy Communion but once a day (except in very, very limited circumstances).