I'd listen to your sponsor, had she suggesteed anything else than ignore him? Is he sayins anything constructive about your program, i.e. hurry up with steps x or pray more etc, or is it just nagging?
I'm afraid with the best will in the world the dating thing will somehow figure in this...i understand why people date in the rooms everyone gets lonely but things like this do happen unfortunately...its happened to me at work in the past and when she gets dumped slowly im not doing the job right anymore...same thing..i think they call it shitting on your own doorstep;-)
Hope it gets some resolution for you soon, may just be a grin and bare it thing until his next love comes along?