Was asked a question this morn…”I have a low sex drive, do you think my partner is cheating on me?”…and I gave the question in this form as to not isolate to gender or preference because these things happen to everyone whom is intimate. 1st things first, there is not enough info to properly answer as it was vague in scope but, I will say that this is a very delicate topic & you want to believe the partner is understanding of that but everyone is different and the best advice I can offer is just keep communication lines open, don’t either of you shut down because resentment, fear, lack of understanding and empathy can be the downfall here.
Intimacy isn’t just physical and that’s something I want everyone to grasp here, so the lack of it can be damaging and hurtful to someone that doesn’t understand or relate. Maybe the one in need is seeking that intimate connection and it’s not being fulfilled and that can create doubt in one’s mind. But to the question, are they cheating, well I don’t know and again you want to have faith that they haven’t, wouldn’t or don’t. It’s not a cause or justification but the fact that you are concerned may mean you see signs or you are just paranoid due to changes in your relationship with your partner.
The 2 of you must communicate your sides and points of view in this because that’s very important to the success of your situation. Find out what they need from you and what you need from them be it understanding or methods and means to help increase the drive. You must work as a team with this and I’m not guaranteeing victory by doing this but it’s much better than the alternative of not. So sit and talk about it, it’s tons of information online that can help but don’t just let it go untouched. Your partner may not even know the WHY in regards to your low drive and a good talk may aid in the understanding and a shift in their attitude and possible need for it as much.
Hope this helps some and I know it didn’t answer the question directly but again that’s not something I would know off hand just off the information provided, best of luck.