If you are in a relationship and she does not condone lying, then withholding information is lying.

Even the fact that you felt you needed to download tinder (you feeling insecure or doubting your partner) shows there is something that is not working in your dynamic with your partner. So, there *is* something that needs speaking about, truthfully, with her.

Brushing it under the rug is not enough - what if a similar situation arises in the future? Nip it in the bud now.