The need to fart kills my orgasm! Advice please!!!

Every time i have sex, i always feel like i have gas or need to let out a little fart. I feel like if i relax my body completely, i will accidentally let some gas out, and thats my biggest fear. This results in me being in my head and trying to clench his dick and clench my butt so i dont fart. For example, when i masturbate at home, whenever i cum theres some gas that leaves my vagina. Im scared for my boyfriend to hear that and its embarrassing, this making it impossible for me to cum with him. On the other hand, my ex boyfriend loved all my fluids, he loved anal, loved messy dirty naughty sex. So i came super fast with him. Ughhhhh i dont know! Advice please?