I'm not 100% sure he has. My personal belief is that he hasn't. Or if he had his encounter w/ omegas before it had left him a distaste or aversion for omegas thus his being w/ betas only. He only socialized w/ betas and as far as we know, has only been with betas sexually. He had wanted to avoid the situation that which he had ended up in with an omega - being affected by their pheromones during his rut, after having turned them on with his own pheromones, where he has no control over himself and loses all reason, at the mercy of pheromones and sexually driven madness, which results in marking and impregnating. We don't know what he has done prior to his relationship w/ Noah, or after having been marked by Noah. We are only assuming that alphas have strong sex drives and so need some kind of partner/partners. So far as we can tell, Ian goes thru his heats alone. If his ruts can only be alleviated by omegas and he doesn't want to do it with omegas and if betas can't relieve his rut then perhaps that is why he chooses to go thru it alone. At least, that's what has happened at the time Noah had gone to find him. He doesn't sleep around, at least, we can see he had been celibate during the 6 months of friendship w/ Noah until they became FWB which was another couple of months. The school year is at least 9 months so he wasn't with anyone else during that time. But his sexual history has not been revealed yet. Everything is just an assumption based on other works. And not all works portray alphas as horndogs either.
So what if he did???? #－.－) like you didn't whore yourself too. You piece of sh**