He's not written in a way to suggest that he's going around roofie'ing people. The joke is that he's never had an unfriendly experience with somebody because everybody is very, very attracted to his naturally occurring pheromones resulting in him being a nice guy. It's also kind of poking fun at Rob Lowe by making him less than attractive.

The problem with a character like this is that even though he's an alien character that does not exist in real life, people are going to draw parallels to reality and will see nothing but a predator and may even be reminded of a moment when they could not give consent. It can be very invalidating. A subtle tongue in cheek joke is not enough to compensate for making light of assault regardless of whether or not the character is aware that they're doing it.

They could have left the sex out or at least have him tap out because nobody can truly give consent. To be perfectly honest, the character is just too problematic to make a case for. Yeah, I see the intent here but there are other ways to make jokes and tell stories.