I think giving or receiving anal or oral sex counts as losing virginity. In many peoples sex lives those elements are more important than penetration. The intercourse definition just fails.
I had given and received oral sex very frequently with my first gf for months on end before we first fucked. It was a very small and unimportant and unimpressive step then. we had already learned to really blow each others minds out and then we clumsily did our first fuck. we just wanted to get back to where we were.(Later btw we got more experienced and interested in fucking) I wouldn´t say the first time I fucked is when I lost my virginity.
I´d say the first time someone gets you off, or you get someone off.