It is because when we eat some thing sweet the tongue buds tastes it as sweet and sent signal that the thing is sweet , the message remains constant for sometime in the brain that tongue is eating something sweet . but when we drink tea the tongue tastes it and sent message that it is sweet whereas our eyes say that we are drinking tea but for tongue the thing is sweet so brain has that message already so it seems to be less sweet or nor sweet .

hope it help u
pls mark it as brainliest answer

2 3 2
your answer is not a sufficient and exact answer.
When you eat sweets a lot, your taste is used to that amount of sweetness. When you eat sweets again, it doesn't feel sweet because it is relatively not sweet enough. However, eat something relatively more sweeter, you will taste sweetness again.
ok but the correct answer till now is that when we eat sweet our tasted buds are relatively molecule with it and very small amount of taste buds would left which would receive the other taste. so the more taste of sweet will be the dominant over other taste.