Is sex important in marriage decision making?

Have any of you ever thought about sex when accepting to marry your other half? My boyfriend is rubbish in bed- I have tried everything I can to stimulate things and make our sex life better but he isn’t willing to explore. He is more of the old school men that would hump inside you for a minute and that’s it, goodnight. I keep thinking about my ex, oh did he know how to satisfy me in bed! I love my boyfriend with everything in me. He has been talking about wanting us to get married. Is it selfish of me to be thinking about turning down his proposal because I can’t imagine a boring sex marriage. He has every other qualities I love in a man, but just lacks sexual ability. I’m so confused. Although I haven’t cheated on him in our 2 years of courtship, I fear that I would want to seek pleasure outside in marriage if I get married to him

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Some of yous are already judging me. You have no right to tell me that I do not love my boyfriend!!!! Absolutely no right!!! If I didn’t love him, I wouldn’t be thinking about overcoming the barrier that we may have in our marriage. If I didn’t love him, I wouldn’t be considerate of his feelings. If I didn’t love him, I will be doing so many things that I am not doing. Now I make reference to my ex boyfriend and our sex life and I am getting judged for that too. What’s wrong with everyone!! I can’t speak about this to my friends without feeling like they would mock my relationship or judge me. I clearly can’t discuss this on here either because I’m having people tell me I do not love my boyfriend