How do I tell that my boyfriend is talking to another woman as he's been acting different towards me like depriving me of his affection?

Telling me it's not about sex all the time , it may be because we've been arguing more then usual. I try and talk to him about my feelings and we just get into an argument as he thinks I'm having a dig at him when I'm just trying to express what I'm feeling. Like he's accusing me of cheating when I haven't! Says I have too many male friends he doesn't like it

But yet he always takes his phone with him to the bathroom and when we first started seeing one another he didn't have his phone on him constantly, he turns his phone off around me it's always on silent.

He gets defensive when I ask a question arghh saying I whinge to much.

How do I tell that my boyfriend is talking to another woman as he's been acting different towards me like depriving me of his affection?
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