I just called my DH , my husband for the first time, while on a date. I paused and thought about it and didn't correct myself. I use to refer to him as Richard, or my late husband. But it suddenly seemed like a lot of effort.
I am remarried and still say my husband, then usually clarify as my late-husband or my first husband. Same with my new husband, I either call him my husband or my new husband.
I wouldn't worry about the date thinking it is weird...he'll have a heck of a lot more issues to worry about if the relationship progresses, so if he can't handle it now, he never will be able to. My new husband is great, but still has his moments of insecurity, regarding how much I love him versus my late husband.
PS--There are widow/er boards out there as well for both younger and more traditional (i.e. older) widow/ers.