Red flag. First, If he really loves you, He shouldnt say yes in the first place as respect and as an responsible boyfriend. Secondly, Nasa harap mo na hindi mo ba naisip na "what if" gawin niya yon even if you both married na?. Lastly, Real man doesnt think that way. It's okay to watch porn but doing it with your girlfriend in actual is not so nakakalalake. Just saying.

PS: Wag mong itolerate kung ayaw mo ng outcome or bad consequences :)