I was thinking on a way to cast haste on an enemy, and then stop concentrating on the spell in the enemy's turn (no action required). The idea is to make the enemy waste 2 turns.

The last paragraph on the haste spell says 

> When the spell ends, the target can’t move or take actions until after its next turn, as a wave of lethargy sweeps over it. PHB 250

My interpretation of this is that if the caster stop concentrating on the spell the target will lose his next turn, and if I stop concentrating on the spell in the targets turn he will lose his current turn aswell.

The spell needs a willing target, so we need to "convince" him that he wants that spell.


My ideas so far:
With spells like *charm person, mass suggestion*.
With spells that have concentration like *dominate person, suggestion*. I don't know how concentration will work in this scenario.
*Bluffing* the target. A lot of DM fiat here.

Will these ideas work? Are there more ways that the ones I've thought?