is this guy at my work weird or am i imagining it?

[ladylee]

new job, other new starter. im a female, hes...well a he... he has a girlfriend ten years younger and very insecure, they met on the internet, all seems very hush hush. so, he started off very nice, too nice, everyone at work thought he was nice and when he asked us all for our mobile numbers we obliged. so, ive been working with him a few weeks when he says "dont tell my girlf ive got your number shes threatened by the girls at work" and i thought, hmm thats not good, but when she comes into our workplace i am very friendly to her. two months on, we leave work at the same time and his girlf meets him, i say would she mind if i walked home with you guys....its dark, they are walking the same way and we are leaving at the same time. she seemed very friendly and chatty and i was pleasant to her, making sure she wouldnt think i was trying to alienate her. later i get a text from him that says "sorry" and i say "bout what?" and he says "didnt want you to think my gf was annoyed at you" im like "i didnt think she was, she seemed cool" and hes like "no she was fine" next day at work, he says "sorry if i made you feel awkward, my gf was moody before we walked home, nothing to do with you, its fine" and then he tells my friend, another colleague "my gf was snappy cos (insert name here) walked home with us last night. i mean, he seems to be stirring stuff up, like he wants ppl at work to think theres something going on with us!!! all i did was walk home, thats is, i mean hell what a mistake, im like 27 years old and he is 28, we are bloody adults, whats with all the high school stirring?! should i tell my boss? the other staff think he is very odd...