He wanted me to smack him

So today my boyfriend surprised me with a very random request when we were having sex he asked me to smack him in the face and choke him because he wanted to see how he’d react. I usually am get open with doing new things and I have no issue choking him because it gets me off as well but smacking him I just couldn’t do. I thought it was taking it a little too far. But now that I think about it should I do it? It might be something he likes and I love doing things he likes and I usually do anything and everything. Does anyone have any input or advice?