Assalamu Alaikum
1) If i slander my friends, they have no sad or enmity towards me. They just take as a fun . Is these type of slandering haram?
2) can i give money to orphanage care taker for buying food or cloth for the orphans as an expiation for breaking oath?
Jazakkallahu Khairan

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

In regard to your first question, uttering obscene speech such as insulting or slandering and the like is forbidden; the fact that the one to whom you uttered these words does not mind is not a justification, or that what you said was as a joke, so it is not permissible to joke like this.

Abu Hurayrah narrated that the companions asked the Prophet : “O Messenger of Allah, you are joking with us.” He said: “Indeed I joke, but I speak nothing but the truth.” [Ahmad and At-Tirmithi]

Al-Khadimi said: “The condition of its [joking] permissibility, in word or deed, is that it should not involve lying or intimidating a Muslim, otherwise it is forbidden.”

Therefore, you must repent sincerely and not return to such a thing again.

As for the second question, please send it separately as per the policy of our site.

For more benefit on lying when joking, please refer to Fatawa 394282, 350794, 345604 and 335944.

Allah knows best.