Question about mortal and venial sin

Hey there. I’m a Protestant (just so you know) and I have a young co-worker who claims to be Roman Catholic. I say “claims to be” because his manner of behavior does not give any evidence of being what I would hope a faithful Catholic would be. He’s incredibly rude, mocks the fact that I’ve chosen to be chaste until marriage, brags about his past sexual conquests, and cusses like a sailor. I’m trying to think of a way to show him the error of his ways and had an idea that I would do so by reminding him what his own church teaches regarding some of these things.

Now then here’s my question. Is he committing a mortal sin or a venial sin when he acts the way he does towards me, specifically, when he says “F*$% you” as he’s prone to do (he thinks he’s being funny). I’m worried about this because not only is he making Christ look bad, but he’s making Catholicism look bad by claiming to be a Catholic and acting this way.

So what are your thoughts my friends?

Hello C.F, Sounds like a bad case of immaturity, Pray for him , give him time. What ever you do, ask the Lord to help you , how to respond or not respond?:(Carlan

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I kinda wanted to ask him if his priest would approve of what he’s saying to me. I suspect, however, that he’s only a nominal Catholic at best and not a true follower of Jesus Christ. Some people think that being born into a Catholic family and being baptised makes them a follower of the Lord, but I believe that how we live our lives shows just who’s follower we really are.

One must live ones baptism…follow Christ.

Certainly Pray for him…and know that one never knows what kind of background a person has had…

here is this section of the Catechism on Chastity …

and on sin:

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