Answer : In my opinion...

Well, I would say, from experience, that it is easier to make a stranger smile.
From experience because when you say a sweet 'hello' to a strager walking down the street....they smile and say 'hello' back as well.
And...it is easier to make a loved one laugh as well. Because...as we have usued the word LOVEd one...then obviously the easier emotion would be the positive emotion.
Happy motivations are always easier.
The HARDEST among the four would be to make a LOVED one cry. Why?
Because it will likely involve a great deal of perfidy in it.

*Perfidy-breaking of a faith.

Should Love be taken SERIOUSLY or EASILY?

Answer : In my opinion...

Love is something that makes you forget your worries and enjoy life. Love is something that reminds you that nothing else matters...and everything matters...at the same time.
One word frees us of all the weight and pain of life; That word is love.
Only when we give joyfully, without hesitation or thought of gain, can we truly know what love means.
The spiritual meaning of love is measured by what it can do. Love is meant to heal. Love is meant to renew. Love is meant to bring us closer to God.

So tell me...do all those things sound like Love is a serious thing?

No....
Yes...there is a responsibility and you have a part to play in love...but...it's all that like the grains of a sand.
If you clutch them too hard...they'll drigt away to the ground.
So if you take LOVE too seriously, forgetting about what it's real meaning is, then it'll also shatter to the ground with a broken heart...or hearts....with it as well.

Our true identity is to love without fear and insecurity. Our higher potential finds us when we set our course in that direction. The power of love and compassion transforms insecurity