Is she cheating?

My friend (M30) and his girl (F34)

He asked for my opinion and I reckon she might be.. what is the consensus?

Evidence:

• Hides phone whenever he comes near, won’t let him touch it, or switches apps

• Took her lingerie when going out with the girls for karaoke, he only noticed by chance, but caught her putting it away when she got home. When confronted said it was a “lingerie party” and “women do that” (also stayed the night)

• Goes out with girls from work but sleeps over sometimes, has happened 4 times in 2 months, also new behaviour. She never goes out or sleeps over anywhere.

• Has been fixating on getting in shape, started Ozempic and gym

EDIT:

More information from a chat I just had with him:

• A guy he doesn’t know has been appearing at functions they are at, apparently an old friend. Though she apparently didn’t invite him, they do share close friends.

• She has in the last 6 months been working back late, sometimes not getting home until 7-8pm, she works 9-5.

• She has new perfume

• Sex has dropped off significantly