My bestfriend since elementary is a muslim. well her family is but she's not religious. During uni, she fooled around with many boys, drank, party, went on dates with guy she meet on tinder every weekend to have sexual intercourse.

She has experienve talking/dating multiple guys at once, and though i never supported her behavior, i let her be.

Then when she graduated university, she said she wants to marry rich and her parents tells her which guy she should "seduce". She finds a really nice muslim guy who fits her parent's standard. hes rich, super kind, gets her flower kind of guy. he thinks she's an innovent virgin who only studied, never had a boyfriend, etc.

All she talks about him with me is that she "loves" how he believes every word he says, she will lie to him about her body count. I think its messed up but again, I dont want to ruin anything.

Until yesterday, I meet him for the first time, and he is genuienly the most warm-hearted, lovely guy. we were at dinner together and he goes "since im Sandra's first for everything, I want it to be special ad treat her right". When i heard him say that, I thought to myself wow, he really likes her. (i dont think he knows theyre dating for marriage yet)

On our way back home with my friend, she goes "see i told you he's an idiot who believes everything i say".

I feel so bad for the guy. So guys, would i be the asshole if i tell the guy the truth about my bestfriend or should i just not say anyhting.