Partners taking long vacation

I'm a partner in a window and storefront manufacturing and installation business. We have 3 main partners (I'm one of them) and 4 small partners. 1 of the main partner is semi retired and pretty much not doing much. The 4 small partners handles different departments (office, shop management, production, installation). Now Chinese new year is coming up, suddenly today 2 of the small partners notified us via our group chat that they will be taking a Chinese new year vacation about 4 to 5 weeks on slightly different dates. Now I take small breaks here and there on holidays, 2 or 3 days connection major holidays, and 1 big break 2 weeks max in the summer with the family. But I can never imagine taking off 5 weeks. And of course I'm pretty much the main guy who over see everything on the business and the only one who actually keep pushing new ideas to make the company better. I also bring my laptop with me on vacation because that's what I mainly do, dealing with customers and handling installation projects and managing all the financials of the company. I'm just upset that these "partners" can just push away their responsibility and throw it on us other partners and not feel bad at all. What am I supposed to tell these people? Am I wrong to feel upset that they want to take a long break from work?