<human>: Can you summarize the given text in a few sentences?

My fiance and I got engaged about 5 months ago and I am pretty sure that he is cheating on me. He has been acting very suspicious, for example, he says he is out with his family and when I ask his sister how the dinner went, she says they never went out and she has no idea why he would say that. Sometimes I see him texting someone and when I come near, he immediately closes it. One of my friends has also told me that she saw him with another girl during dinner and when I asked him he denied it. Also, he is extremely over protective of his phone. He takes it with him to pee, if I have to use it to call someone he dials it for me and then takes it back. Once, I wanted to play a game on his phone and he physically wrestled me to take it out of my hand. 

I know snooping is bad, but honestly I don't care. I have already decided I am going to end it but for my peace of mind, I just want the whole truth and I know my fiance will not give that to me. I have confronted him many times and he does not give me anything. I don't want a lecture on how I should not snoop or how I should just pack my things and leave, I just want to know the truth and at this point snooping is the only way to do it. Any ideas on how I could possibly take it for a day or two without him suspecting that it is me? We do not live together and he never leaves it just lying around.
<bot>: My boyfriend is cheating and I want to know the whole truth and snooping is the only way to do it, how do I snoop through his phone without him knowing when he always has it with him?