Someone a girl continuously has sex with, but you do not consider yourselves in any sort of relationship. "Friends with benefits," possibly minus the "friends" part. No strings attached, a purely sexual relationship. Pseudo meaning not real, manfriend because girls like men, not boys.
I'm so drunk, I'm going to call my pseudo manfriend tonight to see if he wants to hang out.
I haven't gotten laid in forever, I miss my pseudo manfriend, the sex was so good.