I think there's a difference between trust and being open and honest. You can have both or either/or.
I didn't trust T or L right away. T definitely not. But I was open and honest with them from the start. I believe that helped our bond/attachment grow and it helped build trust.
Trust your gut/wise-mind. If it says go forward, go forward. If it says put on the breaks, then slow down. It doesn't have to be all or nothing. Relationship and the different parts of relationships can be like a wave like the rest of life. As my sister (and Dora) would say: "Just keep swimming"!