In Google Translate it is That was the first time we were alienated from each other. Can refer to some first quarrel or something?
那是我们彼此生涩的第一次 I think it's: It was the first time we were so awkward with each other 彼此 = each other 生涩 = jerky, choppy, not smooth I think the other words are pretty obvious so I won't define them ^_^'
Depending on context, it can be worded a couple different ways that have different meanings. You know best. 1) It was our first time being so uncomfortable around each other. 2) For our first time (doing something), it was rather awkward. Those can both mean the same thing or be different happenings altogether.
Really need context for this, but since it's not provided, the more commom reading = that was our awkward first time [implied: having sex]