I've had a really good male friend for about 12 years now, we've always got on great, always been really supportive of each other etc, just a normal friendship really.
We stayed in touch even when I was overseas for years, have supported/laughed at each other through various relationships, both crap and good ones.
Up till a few months ago we were in contact about once a month, but since a phone call a few months ago he hasn't replied to any texts or emails. It was a normal enough phone call, and he said that he's glad I'm back in the UK and wants us to be friends even when we're old and grey. Since that, no replies to texts, no calls. Don't want to text him and ask him why in case I come across as a psycho stalker 
but it also feels odd just to give up.
DH wonders if his girlfriend has banned him from talking to me, which would make it even more awkward if I did keep emailing (and getting ignored). This sounds ridiculous, but I keep having moments where I see something that would make him laugh and would usually text/call, but feel very awkward about doing that now. Just sad about losing such a long friendship I suppose, and wondering if I'm right just to let it tail off. Any advice would be lovely! 