Can you buy a car or an expensive gift for ex?

Kevin Hart is an actor and comedian, he bought a brand new 2015 Escalade for his ex in her 37th birthday.

She took to instagram to announce it this way "Big shout out to my baby daddy/friend @kevinhart4real for my brand new @cadillac Escalade. We have had our rough patches but God and prayer can change anything. My family for life. Thanks for always having my back. Now all I have to do is throw some Ds on this B*tch!!"
Can you buy a gift for your ex?