Question about TRAP card

the TRAP card is played in the first round. In addition to this first round, will it grant a further 2 rounds, generating a total of 3 rounds throughout the combat if not another combat letter is played? Or will this card grant 3 rounds beyond the first, totaling 4 rounds throughout the match if not another combat card is played?

Name: Trap
Cardtype: Combat
Only usable before range is determined on the first round of combat.
During the press step, if any Methuselah has played a card earlier in the current round or during the two previous rounds, the Trap automatically provides a press to continue (either combatant can press to end).

Easiest to take it round by round to answer the question:
Round 1: Trap played. Press step was a combat card played? Yes (Trap), press to continue.
Round 2: Was a combat card played? No. Was a combat card played in the previous round? Yes (Trap), press to continue.
Round 3: Was a combat card played? No. Was a combat card played in the previous round? No. Was a combat card played two rounds previous? Yes (Trap), press to continue.
Round 4: Was a combat card played? No. Was a combat card played in the previous round? No. Was a combat card played two rounds previous? No. Trap's text does not provide a press.

If someone plays a card in a later round Trap would start its evaluation all over beginning with that round.

He must not have liked my (extremely similar) response in FB chat

Easy way to calculate: it provides 3 presses. This amounts to total of 4 rounds of combat if no cards are played afterwards. (Trap itself is played at first round at least)