I've got my brother to play WoW, I was originally brought to play it when my friend and his brother (who I am also mates with) began playing it and invited me to join them. I don't really think anything of it, it's a fun game and it's only a time sink if you let it be.
More specific to the question, a girl I know told me to renew my Aion account to play with her. I was in the same guild with her and her boyfriend for all of the time I played it. To be honest though, the situation was fucking insane. She openly told me she wanted to fuck, and expected me to keep it a secret from her boyfriend, who knew that she had an interest in me. Her boyfriend also knew that she was currently on a break up period with her other boyfriend for a while, so he was more of a fuck buddy that she also met on Aion.
I just completely quit when she started going on webcam half naked and started inviting me to her house every weekend, and getting pissy when I said no. I liked playing Aion with them, and I'd probably say yes if someone asked me if they wanted to play an MMO with me regardless of gender, because I like playing MMOs with people, but in this case I just could not be fucking bothered.