So we've been seeing each other for a few months now and have sex quite frequently. I've learned what she likes and what gets her off but I have a bit of an issue pulling it off.. When she gets close she tightens her muscles and its like someone flips a switch for me.. suddenly I'm about to finish. We'd basically cum at the same time only there's a problem.. she wont' let me wear a condom and doesn't want me to bust inside.. so I have to pull out and it happens to be right before she's about to cum. Every damn time she gets close it happens. I don't even feel like I'm close at all right until she starts tensing up when she gets close. It doesn't matter if its 2 minutes in or 10, every damn time. She tells me she hates the way condoms feel and would rather keep trying without.. so I have no idea what to do. Advice?