it is a little weird that they are close in age but he probably would have brought up the fact that ellie is closer in age to him than she should be anyway so it's not like it's this huge weird age gap. plus his dad is a lot older than ellie too so that's just kind of the norm in their family as weird as that is. i think that after the first couple of awkward meet ups he would have gotten more used to the idea of them being together and really stared to try to get to know her.