EMB-175 flight crew reported a runway incursion during taxi to gate.

Narrative

Taxiing back in from flight ABCD ZZZ1-ZZZ Day 0; Captain and I were number 4 in a grouping of 4 aircraft taxiing back to our gates on taxiway 1. The first 3 of our group was cleared to cross runway XXC at 2 and we were given "turn right 2 hold short of XXC." I seen the CA write it on the FMS scratch pad and we continued towards 2. As we turned on to 2 the CA confirmed with me "we are holding short after this right" I initially thought he meant after the turn onto 2 but he was implying short of the next runway XXL. Once my brain caught up to what was implied I stated "we are short of this runway here" the CA APPLIED the brakes but with the wet taxiways we slid just over the hold short line. I advised tower immediately that we were over the line but they did not issue a go around after their reply. This prompted the CA to call them back and advise again that we were over the line. Tower then issued Aircraft Y a go-around. We crossed and continued to the gate with no further instances."Cause: Lack of sufficient verification that the captain understood the taxi instructions.Suggestions: Always read back and verify with crew to ensure all parties understand."