I LOVE BJ The meaning will shock you

So here I am with mrs Njenga at kivingoti soko Mjinga on sagana nyeri highway...... she insists on buying some vegetables and being the gentleman I am (ahem ....mostly because I'll the primary consumer) We stop. I'm given a seat and just observe
...... this gentleman comes along and I can't help to notice his Tshirt I approach him and request if I could record him he agrees and I ask him if he knows what the words on his Tshirt means the explanation left me with stitches.....(