Is your boyfriend a liar?

Here is a story of my friends, she says as follow:

My boyfriend lies about the stupidest shit! 
Tonight, thanksgiving, he lied to me right to my face in front of his own family. He had been gone for a while (half hour or so) and I had looked inside and out for him, and couldn’t find him. His mom called down to a friends house and the friend said that yes he was there but he left about 5 minutes ago (him and his brother walked). 

When he came back and I asked him where he was, his response was ” we went down to the lake to drink a beer”. Not knowing his mom had already talked to the friend and we knew where he had gone. He didn’t tell me he was leaving, he was there one minute and the next he was gone. When we left I asked him again and he continued to lie to me until I said well your mom called down to Lenny’s house.. And he said than I guess u know where I was actually at. There was ok reason to lie. He just went to say hi to the guy. But for whatever reason, he lied. He does this very often.

 He will do favors for his aunt who lives behind us, and lie to me about it until he’s upset with her about something than he will say “well I ain’t doin this for her anymore or that” and it would have been the first I heard about it, I would have heard a different story. Or when he was working with his last boss, they would go do stuff after work and he would lie to me and say he had been working the whole time. Like they would ride around to different shops buying shit his boss needed, than would tell me he had been at so and SOS the whole time mowing the lawn.

 The best one was when he was working at a factory and he would take breaks with this one girl and not talk to me. Mind you we were seeing each other an hour a day MAYBE, so the 5 minute phone call meant a lot. He would lie to me and say his phone was dead or he didn’t have the time.. But a friend of mine who also worked there told me that he was taking breaks with this girl and another guy. He said later that they were just friends, and that she started to come on to him and he told her he has a girlfriend, (the night she came on o him was the same night he told me about her comin on to him, so as soon as it happened he fessed up).. But it makes me wonder if they were just talking than why lie? He will lie about shit from his past too, like certain girls or whatever. 

The thing is, is I can’t lie a single bit about any of the past guys before him, if he finds out I lied about any he flips. But he will lie to me about them. I don’t understand?

 I think it’s best if him as I just go our separate ways either until he can learn to grow up or quit lyin or something. Otherwise I guess it just wasn’t meant to be.