Help - how to deal with my bestfriend's relationship?

So my best friend has recently got back together with her boyfriend and the way she's behaving is really bugging me. She only wants to talk about him and how 'cute' he is and she gives waaaay to much information about the physical stuff that makes me kinda uncomfortable. When we are together she is constantly texting him, even though she hates it when others are on their phone when she's trying to talk. I don't mean to be the salty single bestfriend but honestly I feel like its putting a lot of strain on our friendship.
How do I tell her I don't always want to hear about their relationship (especially the parts that are a bit tmi) without hurting her feelings? she's pretty sensitive so I wouldn't want her to feel like she can never talk about him