This could be due to many things. Does your partner satisfy you in bed? Perhaps your old partner did and your new lover doesn't and you are comparing the two. In which case you need to point them in the right direction by making positive noises when they are doing things that are working and guiding them when they are not. Everyone is different so what worked with exes won't necessarily work with new partners. If they don't get the message then some verbal pointers to give them the best chance of pleasing you. The important thing is to give them feedback that won't damage their confidence by also telling them what they do that makes you feel good.

Maybe you lack energy through diet, stress, or being overworked and the idea sounds great, but when it comes down to it- you lose all interest because you feel physically unable to do it. If this is true, then perhaps you need to look at eating foods that will give you more slow release energy, or look at ways you can reduce stress and your workload to improve your physical wellbeing or change the time you normally have sex. Regular exercise will also help improve your fitness and also your stamina too.

Is your sex life repetitive? Perhaps you need to look at making it less predictable if so. Sex toys, sexy outfits, role play or trying new positions could be a way to make your sex life more interesting again if it always falls into the same routine. This might give you the incentive to move past foreplay.

Sex lives need constant nurturing with good communication and new ideas in order for it to be appealing for both partners. Mutual pleasure comes with time and patience- so in any new sexual relationship there are bound to be a few compatibility issues at first. Try to explore what the issue might be and keep your partner posted along the way so you can work together to make sex something you are interested in again.